A specialized mass spectrometer is proposed as a universal detector for liquid chromatography applications. This device will be highly suited to the analysis of organic compounds in complex fluids and will allow biomedical researchers to both identify and quantitate various species of interest rapidly and with no previous training in the use of a mass spectrometer. The instrument, an atmospheric pressure chemical ionization-time of flight mass spectrometer (APCI-TOF-MS), will provide for the efficient ionization and delivery of analyte species to a mass sensitive detector with electronic integrating capabilities. Various chromatography conditions (flowrate, buffer concentration, solution conductivity) will have minimum impact on the performance or reliability of the instrument by virtue of a special ultrasonic nebulization inlet system which has been specifically engineered for the delivery of liquids to analytical instruments. As a package, the combination of the ultrasonic nebulization system and the APCI-TOF-MS will provide solvent-independent operation over flowrates ranging from capillary electrophoresis range to microbore LC range (0.1- 400 mu l min-1). The TOF mass analyzer and integrated transient recorder will allow even the most rapid elution conditions to be maintained while delivering high sensitivity and very high subsecond dynamic range.